15 Mar 24 Interference, Diffraction

Today: Interferometers, Soap Bubbles, Small particle diffraction Glory from airplane. Colorful diffraction by Frank Peters on Flickr.

Clicker question—Single-Slit Diffraction ,[object Object],B A

Clicker question—Single-Slit Diffraction ,[object Object],B A Smaller aperture = MORE like a point source. Therefore, MORE spreading. Aperture much wider than original beam -> should not affect the beam http://www.lon-capa.org/~mmp/kap27/Gary-Diffraction/app.htm

Clicker question—Double-Slit Diffraction ,[object Object],A B C http://www1.union.edu/newmanj/lasers /Light%20as%20a%20Wave/light_as_a_wave.htm

Clicker question ,[object Object],A B C Double-Slit (Two single-slit patterns Interfering with each other) Single-Slit Hexagonal Aperture

Because of interference , the double slite diffraction pattern is not simply the “sum” of two single-slits Single-Slit #1 + Single-Slit #2 Double-Slit http://www.saburchill.com/physics/chapters2/00081.html

Double-slit Interference ,[object Object],[object Object],http://www.walter-fendt.de/ph14e/doubleslit.htm Ripple tank: http://www.youtube.com/watch?v=-8a61G8Hvi0&feature=related

Clicker question—double slit interference ,[object Object],[object Object],[object Object],Bright or dark?

Clicker question—double slit interference ,[object Object],[object Object],[object Object],Path lengths are equal

Clicker question—double slit interference ,[object Object],[object Object],[object Object],Path lengths are equal Spacing depends on wavelength

Double-slit interference can only be explained by waves. ,[object Object]

[object Object],[object Object],In the double slit experiment for electrons, do you expect to see two bands or do you expect an interference pattern?

This little video explains the wave phenomena nicely ,[object Object],[object Object]

Are electrons particles or waves? Hitachi double-slit with electrons http://www.hqrd.hitachi.co.jp/em/doubleslit.cfm

Electrons (matter) also behave as waves! Hitachi double-slit with electrons http://www.hqrd.hitachi.co.jp/em/doubleslit.cfm

Let’s do an experiment! ,[object Object],[object Object],[object Object],[object Object],[object Object]

Microwave Michelson Interferometer ,[object Object]

Clicker Question…Interferometer ,[object Object],[object Object],[object Object],[object Object]

Clicker Question…Interferometer ,[object Object]

Interferometers are great physics tools ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Also in space! LISA (2018)

Much of the physics of polarized light, diffraction and interference are illustrated by a CD & DVD Player! ,[object Object],Diffraction Grating Tracks in a CD Spacing about ½ micron Pits in a CD

Much of the physics of polarized light, diffraction and interference are illustrated by a CD & CD Player! ,[object Object],http://hyperphysics.phy-astr.gsu.edu/HBASE/audio/cdplay.html Destructive interference for detection

Information density is limited by laser spot size (and thus wavelength of laser) Blue lasers more difficult to make than red lasers

Scattering off small particles also causes diffraction ,[object Object],[object Object],[object Object]

Interference from thin films ,[object Object],[object Object],Fast Slow Fast

Homework problem Thin film interference in your kitchen ,[object Object]

15 Mar 24 Interference, Diffraction

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à 15 Mar 24 Interference, Diffraction

Similaire à 15 Mar 24 Interference, Diffraction (20)

Plus de Steve Koch

Plus de Steve Koch (20)

Dernier

Dernier (20)

15 Mar 24 Interference, Diffraction